The advent of magazine-fed firearms follows centuries of advancements in firearm technology. The earliest firearms required a user to load loose powder and a lead ball into the barrel of the firearm before each shot could be taken. The practical limitations of this design were readily apparent, namely, the inability to fire rounds in quick succession, leading to various innovations in firearm design. Initially, gunsmiths focused on developing firearms having multiple barrels, such as double-barreled shotguns, pepper-box guns, etc. or multiple chambers in which round may be inserted, such as the revolver. However, the addition of multiple barrels or multiple chambers, such as those in the double-barreled shotgun and the revolver, respectively, led to increased weight and complexity.
In an effort to increase the speed at which a user may fire rounds while keeping the weight of the firearm to a minimum, innovation at this time focused on superposed loads, which enabled a user to load multiple projectiles in a single barrel. Like the multi-barrel and multi-chamber designs that preceded it, firearms incorporating superposed loads within their designs suffered from overly-complex mechanisms and an inability to be easily mass produced.
Integrated cartridge type ammunition consisting of a case holding the propellant and the projectile, a rim, and a primer to ignite the propellant was developed to further increase the speed in which a user may fire a round. Cartridges of this type eliminated the need for a user to pack a barrel with propellant, wadding, and the projectile each time the user wanted to fire the weapon. An early form of the cartridge type ammunition is the paper cartridge, which was popular for use with the Sharps breech-loading rifle, amongst others. Further innovation focused on increasing the durability of the cartridge and the ability of the case of the cartridge to seal the firing chamber such that more powerful cartridges may be utilized. Solid-drawn metallic cased cartridges are one of the most popular types of cartridges used in modern firearms.
Although cartridge type ammunition significantly decreased the amount of time required to re-load a firearm, there was still room to improve. The next evolution in firearm design was the tubular magazine, in which multiple cartridges could be loaded within a tubular magazine that is permanently attached to the firearm. Once the final bullet contained within the tubular magazine has been fired, the user may reload the magazine a single cartridge at a time. While considered an important step forward in firearm design, tubular magazines continued to have the shortcoming of being permanently attached to the firearm, resulting of the time consuming process of loading individual cartridges into the magazine in order to begin firing again.
The repeater style firearms that were developed during this period, such as the lever action and the bolt action rifle, set the framework for developing firearms that could fire multiple rounds in quick succession. Improving upon these designs, the detachable magazine was developed which enabled users to quickly replenish the number of rounds available to fire by simply replacing an empty magazine with a fully loaded one. These removable magazines included a simple construction having a follower and a spring. As each round is inserted within the magazine, the follower is pushed down against the bias of the spring. Therefore, as each round is fired, the spring biases the follower towards the receiver of the firearm to load another round.
As can be appreciated, however, this design enables debris and other contaminants to gather in the magazine housing or coat the inner walls of the magazine housing in which the follower slides up and down. Because each magazine is reusable, over time, the debris can inhibit movement of the follower within the magazine housing, and in some cases, cause the follower to jam or malfunction.